The package has a debian/watch file, but the last attempt
to use it for checking for newer upstream versions failed with
an error:
In debian/watch no matching files for watch line https://github.com/shimmerproject/Bluebird/tags .*/archive/v?([0-9][0-9\.]*)(?i)(?:\.(?:tar\.xz|tar\.bz2|tar\.gz|tar\.zstd?|zip|tgz|tbz|txz))